Diabetes mellitus and hyperlipemia exist together in a frequency that is much higher than can be expected by chance alone. The mechanisms involved in these interrelationships are unknown. This proposal is designed to evaluate glucose and lipid interaction in various in vitro systems as well as to look at glucose, free fatty acid and lipoprotein interaction and the hormonal influences on these various fuels in patients with diabetes mellitus and hyperlipidemia. It is hoped that by these studies, better insight will be gained into the complex metabolic interrelationships involved and that this might explain the mechanisms resulting in the frequent co-existence of diabetes mellitus and hyperlipemia.